Fuel Flashcards
How many fuel tanks does the aircraft have and what are their approximate capacities?
A Center wing tank
Main Tanks 1, 2, 3 & 4
Reserve tanks 2 & 3
Two surge tanks
FCOM 2 12.20.1
What commands fuel valves to open or close and fuel pumps to turn on and off according to fuel management logic?
Fuel System Management Cards FSMC’s
FCOM 2 12.20.13
Which crossed valves are affected by flap extension on the ground?
Crossfeed valves 2 & 3 close when flaps extend to the T/O position on the ground.
FCOM 2 12.20.13
Which fuel pumps are system logic pumps? in other words, which fuel pumps are commanded to turn on and off by system logic during normal operations?
FUEL OVRD 2 & 3 FWD/AFT
FCOM 2 12.20.3
Trace the flow of fuel to the engines when there are 7700 kgs or more fuel in the Center Wing Tank from blockout.
The CWT override/jettison pumps feed engines 1 & 4
Main pumps 2 & 3 feed tank-to-engine
FCOM 2 12.20.13
Trace the flow of fuel to the engines when there is less than 7700 kgs of fuel in the Center Wing Tank from blockout.
Override/jettison pump 2 feeds engine 1
Override/jettison pump 3 feeds engine 4
Main pumps 2 & 3 feed tank-to-engine
FCOM 2 12.20.13
When do the FSMC’s open the reserve transfer valves?
When the main tank 2 or 3 quantity drops to approx 18,200 kgs.
FCOM 2 12.20.12
Under what conditions would fuel automatically transfer from Main Tanks 1 and 4 to their adjacent tanks 2 and 3?
When main tank quantity drops to 3,200 kgs
FCOM 2 12.20.12
Can fuel be manually transferred from any tank to another tank?
Fuel may be manually transferred from tanks 1 and 4 to 2 & 3 respectively with the overhead panel switch.
FCOM 2 12.20.12
What occurs when Fuel Jettison Switch is selected to either A or B?
It arms the jettison system and displays fuel to remain on EICAS
FCOM 2 12.10.4
Describe how the fuel quantity indication changes upon termination of fuel jettison.
Fuel quantity will change back to white and flash for 5 seconds.
FCOM 2 12.10.11
What occurs when you push either fuel jettison nozzle valve to ON during the QRH fuel jettison procedure?
It activates the override/jettison pumps in tanks containing fuel if the pump switches are on.
FCOM 2 12.10.4
What is the source of fuel for the APU?
Tank 2
With AC power available aft boost pumps 2 & 3 supply the fuel
If AC power not avbl, tank 2 DC pump supplies the fuel
FCOM 2 12.20.12
In general, how are fuel imbalance situations handled?
by opening or closing crossed valves and fuel pump switches.
FCOM 2 12.20.3
What is the impact on the aircraft of excessive fuel imbalance?
It adversely affects CG, drag and fuel economy
FCOM 2 12.20.3
When is an engine on suction feed, and how are suction feed situations corrected?
An engine draws fuel by suction feed whenever main tank fuel pump pressure is low.
FCOM 2 12.20.3
Does the suction feed line go through the main tank fuel pumps?
The suction feed line bypasses the fuel pumps.
FCOM 2 12.20.3
A single Main Tank Fuel Pump can provide sufficient fuel to how many engines?
1 ENG at T/O; or
2 ENG’s at CRZ
A single Main Tank 2 or 3 Override/Jettison pump can provide sufficient fuel to how many engines?
2 engines at T/O or CRZ
FCOM 2 12.20.2
Can the Main Tank 2 or 3 Override/Jettison pump operate when the related Main Tank is below 3200 kgs (standpipe level)?
No, a pump cannot operate below its standpipe level.
Fuel tank temperature is measured in which tank?
Tank 1
Amber below -37*C
Not avail during jettison - replaced by fuel to remain display.
FCOM 2 12.20.1
When does the fuel temperature display on Primary EICAS display in Amber?
below -37*C
FCOM 2 12.20.1
How is the Center Wing Tank fuel scavenged?
By 4 jet pumps (2 pumping into each main tank)
FCOM 2 12.20.2
What three different conditions will generate a fuel imbalance message on the EICAS?
Longitudinal fuel imbalance of 2,720kg between inboard mains and outboard mains + reserve tanks.
FCOM 2 12.30.1
When does the fuel imbalance message no longer display on the EICAS?
When imbalance <450kg
FCOM 2 12.30.1
When does a Crossfeed Valve ON with the bar visible indication mean for Crossfeed Valve switches 2 and 3?
It means the crossfeed is on when commanded by system logic
FCOM 2 12.10.1
What does a Crossfeed Valve ON with the bar visible indication mean for Crossfeed Valve Switches 1 and 4?
The crossfeed is ON
FCOM 2 12.10.1
When are Override/Jettison Pumps 2 and 3 displayed in Cyan on the Fuel System Synoptic?
Armed for system logic operation
FCOM 2 12.10.10
